Biodegradation of polycyclic aromatic hydrocarbons by a bacterial consortium enriched from mangrove sediments

Polycyclic aromatic hydrocarbons (pahs) biodegradation in contaminated sediment is an attractive remediationtechnique and its success depends on the optimal condition for the pah-degrading isolates. the aims of thecurrent study was to isolate and identify pahs-degrading bacteria from surface sediments of nayband bay and toevaluate the efficiency of statistically based experimental design for the optimization of phenanthrene (phe) andfluorene (flu) biodegradation performed by enriched consortium. pahs degrading bacteria were isolated fromsurface sediments. purified strains were then identified by 16s rdna gene sequence analysis. taguchi l16 (45) wasemployed to evaluate the optimum biodegradation of phe and flu by the enriched consortium. total of sixgram-negative bacterial strains including marinobacter hydrocarbonoclasticus, roseovarius pacificus, pseudidiomarinasediminum and 3 unidentified strains were isolated from enrichment consortium, using fluorene (flu) andphenanthrene (phe) as the sole carbon and energy source. the enriched consortium showed highest degradationabilities (64.0% flu and 58.4% phe degraded in 7 days) in comparison to a single strain cultures or mixtures.maximum biodegradation efficiency was occur at temperature = 35°c; ph = 8; inoculum size = 0. 4 od600nm; salinity=40 ppt; c/n ratio = 100:10. in conclusion our results showed that, indigenous bacteria from mangrove surfacesediments of nayband bay have high potential to degrade flu and phe with the best results achieved whenenriched consortium was used.